This is probably in the wrong section but, humidity might damage an unfinished wood but normally no. Just changes the bow a bit from low to high humidity which is rectified by adjusting the truss rod in the neck.
solid body should be ok . i had a classical that went through a really cold winter with me and the finish cracked on the front and sides, i guess that was due to the wood shrinking or whatever the cold does?
also i cant get it over to Australia from the uk as i think the flight would kill it (its handmade and very sensitive)
i know when winter hits here all i have to do is a little adgustment on the truss rods usually and again the same in summer.
Too dry and your neck can warp, your finish can crack. Too humid your neck can warp too. Heat is a factor too, can add to warpage and lossen glued joints etc. Toocold can make things crack too. I'm sure somebody know's more than I do about this. Just treat your guitar like you would a child, and you'll be fine. If you'd be uncomfortable, it's probably bad for your guitar too.